St Petroc was the son of a Welsh chieftain and arrived in Cornwall in the 6th century. He lived most of his life on his own, but ministered among the people of Devon and Cornwall. Many of the churches there are named after him.

His bones were buried at St. Petroc parish Church, Bodmin, but a angry monk stole them and took them to Brittany in France. In due course the monks were able to get the bones back and they were kept in this special box called a reliquary. This box is on display at Bodmin Parish Church to this day. In 1994 the box was stolen but a couple of years later was found in a ditch and returned to the church. The bones no longer exist.